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Myxomatous degeneration of the mitral valve

1971; Elsevier BV; Volume: 28; Issue: 4 Linguagem: Inglês

10.1016/0002-9149(71)90009-9

1879-1913

Richard H. Davis, Benjamin S. Schuster, Suzanne B. Knoebel, Charlés Fisch,

Cardiac Structural Anomalies and Repair

Abstract The clinical, hemodynamic and pathologic features of 5 cases of anatomically proved myxomatous degeneration of the mitral valve resulting in mitral regurgitation are presented. Four patients manifested refractory congestive failure. Examination revealed cardiomegaly, third and fourth heart sounds and a grade 3– 4 6 apical holosystolic murmur transmitted to the axilla. One patient had a late systolic murmur. None exhibited signs suggestive of Marfan's syndrome. On fluoroscopy, the left atrium and ventricle were enlarged without valvular calcification. Sinus rhythm and nonspecific ST-T wave changes were recorded on the electrocardiogram. The apex cardiogram showed prominent A waves. Intracardiac pressures (range in mm Hg) were: mean left atrial 16–46; left ventricular end-diastolic 9–25; mean pulmonary arterial 15–61; right ventricular end-diastolic, 5–29, mean right atrial 3–16. Cardiac output ranged from 2.5 to 6.9 liters/min (Fick method). Cineangiography demonstrated massive mitral regurgitation. Coronary cineangiograms were normal. At surgery, the mitral valve leaflets were observed to be quite flaccid and “floppy”. Papillary muscle and chordae tendineae were normal. There was no valvular calcification. Anatomy of the mitral leaflets demonstrated typical features of myxomatous degeneration including layers and foci of dense, hyalinized, relatively acellular collagen. Among the denser layers of collagen were loose, lightly stained zones with small fibrocytes. Myxomatous degeneration of the mitral valve should be considered among the causes of acquired mitral regurgitation.